1. Field of the Invention
The present invention relates to a micro electromechanical system (MEMS) microphone, and particularly to a wafer level package of MEMS microphone and a manufacturing method thereof.
2. Description of the Related Art
Micro electromechanical system (MEMS) technique has established a whole new technical field and industry. The MEMS technique has been widely used in a variety of microelectronic devices that have electronic and mechanical properties, for example, pressure sensors, accelerators and micro-microphones. Since the MEMS microphone has the advantages of light, small and high signal quality, it gradually becomes the mainly stream of micro microphone.
FIG. 1 is a schematic view of a conventional package of MEMS microphone. Referring to FIG. 1, the conventional package 100 of MEMS microphone includes a MEMS chip 110 and a complementary metal oxide semiconductor (CMOS) chip 120 disposed on a substrate 130. The MEMS chip 110 and the CMOS chip 120 are covered by a metal cover 140 fixed on the substrate 130. The metal cover 140 is used for protecting the MEMS chip 110 and the CMOS chip 120. In addition, the metal cover 140 defines a number of sound receiving holes 142.
In the process of fabricating the conventional package 100 of MEMS microphone, a ratio of the package cost of the package process to the total production cost of the conventional package 100 of MEMS microphone is a percentage of 75%. Furthermore, a big package stress will be generated in the package process. Therefore, what is needed is a new package of MEMS microphone to overcome the above disadvantages and to reduce the production cost of the MEMS microphone.